How to Choose the Right Colorant for Plastic Products

How to Choose the Right Colorant for Plastic Products

Nowadays，plastic materials are used across various industries, playing a crucial role in creating colorful, functional products. Selecting the right colorant for plastic is a key consideration that impacts product quality, cost, and overall performance.

Types of Colorants

Colorants are available in four physical forms:

• Powder (Colourment): Dry pigments or dyes.
• Color Paste: A semi-liquid form.
• Liquid Colorant: Fluid colorant for specific applications.
• Color Masterbatch: A solid additive commonly used in industry.

Among these, powder and color masterbatch are the most widely utilized.

Features of Colourment and Color Masterbatch

1. Colourment (Powder Colorant):

-Advantages: Powder colorants offer excellent dispersibility at a low cost and are customizable in small batches. This makes them ideal for small to medium enterprises, especially for products with lower coloring requirements, such as PVC building materials or EVA soles. They also reduce the risk of resin degradation, prolonging the product's lifespan.

-Disadvantages: Powder colorants can create dust during handling, complicating environmental control. They also pose cleaning challenges for extrusion blow molding machines, as the color powder tends to stick to equipment surfaces, leading to wasted time and material. Additionally, chromatic aberrations (color variations) can occur due to different batches or suppliers.

2.Color Masterbatch:

-Advantages: Masterbatch is dust-free, easier to clean, and offers more stable color consistency, as manufacturers pre-select pigments to reduce color variation. It’s especially useful when frequent color changes are needed.

-Disadvantages: The limited addition of masterbatch (usually 1%-4%) and the short processing time can lead to less thorough color dispersion compared to powder colorants.

How to Choose the Right Color Masterbatch

Color masterbatch has become the preferred coloring method for plastic products due to its superior handling and performance. There are two types:

• General Color Masterbatch: Suitable for multiple resin types, typically added at 1%.
• Special Color Masterbatch: Tailored for specific resins, with an additive volume of 1%-4%.

General vs. Special Masterbatch: Resins vary in their ability to accept color. For instance, resins like ABS and HIPS have excellent coloring properties but low flowability, making general masterbatch less effective. Special masterbatch, with a lower concentration, can achieve better dispersion, especially in thin-walled products, preventing color spots or streaks.

Conclusion: Both colorants have their strengths and weaknesses. Based on experience, after confirming the resin type, it is advisable to prioritize special color masterbatch for optimal results.